Endoscopic system for resection of tissue

ABSTRACT

The present embodiments provide apparatus for facilitating endoscopic resection of tissue. The apparatus comprises proximal and distal barrels. The proximal barrel is adapted to be coupled to an endoscope. A cutting member is disposed within a lumen of the distal barrel and configured to resect a segment of tissue. In one embodiment, a central longitudinal axis of the proximal barrel is radially offset from a central longitudinal axis of the distal barrel, thereby allowing the cutting member to be centered relative to the working lumen of the endoscope. Additionally, the cutting member may comprise at least one viewing window that permits endoscopic visualization of tissue distal to the distal barrel when the cutting member is disposed within the distal barrel.

PRIORITY CLAIM

This invention claims the benefit of priority of U.S. ProvisionalApplication Ser. No. 61/372,271, entitled “Endoscopic System ForResection Of Tissue,” filed Aug. 10, 2010, the disclosure of which ishereby incorporated by reference in its entirety.

BACKGROUND INFORMATION

The present invention relates generally to the field of medical devices,and more particularly, to an endoscopic system for resection of tissue.

There are various instances in which it may become necessary ordesirable to resect a segment of a patient's tissue, for example, toobtain tissue samples or remove potentially harmful or cancerouslocalized tissue segments. At the present time, partial or fullthickness resection of tissue is often left for open surgicalprocedures, resulting in the drawbacks associated with open surgery suchas increased invasiveness and potentially longer recovery times.

There are some endoscopic techniques for cutting and collecting tissue.For example, one or more cutting instruments, such as a needle knife,may be advanced through a working lumen of an endoscope. The cuttinginstrument then may be advanced beyond the distal end of the endoscopeand actuated by supplying an electrical current to the tip of theinstrument. Once heated, the cutting instrument may be positioned toengage and cut the target tissue. The tissue then may be captured andremoved, for example, by using a forceps advanced through the workinglumen of the endoscope.

When cutting instruments, such as needle knives, are used in theabove-described manner, the result may yield an imprecise cutting oftissue. In particular, when a sharp, pointed and/or heated instrument isadvanced distal to the endoscope, a risk exists of improperlymaneuvering the cutting instrument and therefore inadvertentlycauterizing or searing healthy or non-target tissue. Further, in theseprocedures, the extended cutting instrument is generally moved in acircular motion, which may increase the risk of incision to theunrelated tissue.

Other instruments, such as needles, may be advanced through a lumen ofan endoscope and may engage tissue. For example, a biopsy needle may beused to obtain a sample of tissue. However, the size of the needle islimited by the diameter of the working lumen of the endoscope, andtherefore, the needle cannot resect a large segment of tissue.

There is a need for a safe and effective system for the resection of awide range and size of tissue segments during endoscopic procedures.

SUMMARY

The present embodiments provide apparatus for facilitating endoscopicresection of tissue. The apparatus comprises proximal and distalbarrels. The proximal barrel is adapted to be coupled to an endoscope. Acutting member is disposed within a lumen of the distal barrel andconfigured to resect a segment of tissue.

In one embodiment, a central longitudinal axis of the proximal barrel isradially offset from a central longitudinal axis of the distal barrel,thereby allowing the cutting member and the distal barrel to be centeredrelative to a working lumen of the endoscope. The cutting member may becoupled to an actuating member disposed within the working lumen of theendoscope, such that the actuating member is coupled to the cuttingmember along the central longitudinal axis of the distal barrel.Advantageously, the cutting member may be centered relative to theworking lumen of the endoscope, such that when the actuating member isadvanced and/or rotated, an enhanced and centered rotation of thecutting member may be achieved.

The cutting member may comprise a cylindrical main body having a beveleddistal region. A stop member may be provided to limit maximum distalmovement of the cutting member.

Additionally, the cutting member may comprise at least one viewingwindow. For example, a proximal support section of the cutting membermay comprise a plurality of supporting struts separated by a pluralityof viewing windows. Advantageously, the plurality of viewing windowspermit endoscopic visualization of tissue distal to the distal barrelwhen the cutting member is disposed within the distal barrel.

A first separating segment formed between the proximal barrel and thedistal barrel may prevent the distal barrel from being advancedproximally over the endoscope. A second separating segment formedbetween the proximal barrel and the distal barrel may limit proximalmovement of the cutting member.

Other systems, methods, features and advantages of the invention willbe, or will become, apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be within the scope of the invention, and be encompassed bythe following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention. Moreover, in the figures, likereferenced numerals designate corresponding parts throughout thedifferent views.

FIGS. 1A-1B are, respectively, a perspective view of an exemplaryend-viewing endoscope and a close-up view of the distal region of theendoscope.

FIG. 2 is an elevated front perspective view of an endoscopic tissueresection system with a cutting member in a retracted state.

FIG. 3 is a rear perspective view of the endoscopic tissue resectionsystem of FIG. 2 with the cutting member in an advanced state.

FIG. 4 is an isolated perspective view of a cutting member and anactuating member of the endoscopic tissue resection system of FIGS. 2-3.

FIG. 5 is a perspective view showing the endoscopic tissue resectionsystem of FIGS. 2-3 being coupled to the distal region of the endoscopeof FIGS. 1A-1B.

FIGS. 6-7 are side-sectional views of the endoscopic tissue resectionsystem of FIGS. 2-3 with the cutting member in retracted state andadvanced states, respectively.

FIGS. 8-9 are side-sectional views of an alternative endoscopic tissueresection with a cutting member in retracted state and advanced states,respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present application, the term “proximal” refers to a directionthat is generally towards a physician during a medical procedure, whilethe term “distal” refers to a direction that is generally towards atarget site within a patient's anatomy during a medical procedure.

Referring now to FIGS. 1A-1B, an exemplary endoscope 20 is described,which may be used in conjunction with the tissue resection systemdescribed below. In FIG. 1A, the exemplary endoscope 20 comprises anend-viewing endoscope of known construction and having proximal anddistal regions 32 and 34, respectively. The endoscope 20 may comprisefiber optic components 36 and 37 for illuminating and capturing an imagedistal to the endoscope 20, as depicted in FIG. 1B. A physician may viewthe images distal to the endoscope 20 using an eyepiece 30. A fiberoptic cable 24 may be coupled between the endoscope 20 and a suitablelight source. A control section 23 may be provided to maneuver thedistal region 34 of the endoscope 20, and facilitate actuation ofvarious components associated with the endoscope 20.

The endoscope 20 also may comprise a working lumen 38, as shown in FIG.1B. An auxiliary port 25 may be placed in fluid communication with theworking lumen 38, such that components advanced through the auxiliaryport 25 are directed into the working lumen 38. The working lumen 38 maybe sized to accommodate an array of medical components, such as acatheter, forceps, snare and the like. While one working lumen 38 isshown, additional lumens may be employed. Other features and componentsof the endoscope 20, and variations thereof, are generally known tothose skilled in the art and are not critical to the present invention.

In a conventional procedure, the endoscope 20 may be advanced through anatural bodily lumen, such as the alimentary canal, to a positionproximate a target location. A catheter or other medical device then maybe advanced through the working lumen 38 of the endoscope 20 to thetarget location. Optionally, a needle or other suitable device may beused to puncture through an organ or a gastrointestinal wall to providetranslumenal endoscopic access to various additional bodily regions.

Referring now to FIGS. 2-7, a first embodiment of an endoscopic tissueresection system 50 is described. In this embodiment, the endoscopictissue resection system 50 generally comprises a proximal barrel 60 anda distal barrel 80. As explained in further detail below, the proximalbarrel 60 may be coupled to the distal region 34 of the endoscope 20,while a cutting member 100 may be disposed within the distal barrel 80.The cutting member 100 may be coupled to an actuating member 115, andmay be selectively longitudinally advanced and/or rotated with respectto the distal barrel 80 to resect tissue.

The proximal barrel 60 comprises proximal and distal regions 62 and 64,respectively, and a lumen 68 extending therebetween. The proximal region62 may be coupled to the distal region 34 of the endoscope 20.Preferably, at least a portion of the proximal region 62 of the proximalbarrel 60 is disposed about an exterior surface of the endoscope 20, asshown in FIG. 5. In the embodiment shown, most of the proximal barrel60, spanning between the proximal and distal ends 62 and 64, is disposedabout the exterior surface of the endoscope 20, although any portion maybe coupled to the endoscope 20 so long as a secure attachment isachieved.

In one embodiment, at least a portion of the proximal region 62comprises an elastic member having a first inner diameter in a relaxedstate, and a second, slightly larger inner diameter when in an expandedstate. If the proximal region 62 is elastic, it may be sized such thatits inner diameter in the relaxed state is slightly smaller than anexterior diameter of the endoscope 20, but its inner diameter in theexpanded state is slightly larger than the exterior diameter of theendoscope 20. This configuration allows at least the proximal region 62of the proximal barrel 60 to elastically expand to be disposed over thedistal region 34 of the endoscope 20. Once in place, the proximal region62 will be allowed to return to its relaxed state, thereby securelyengaging the proximal barrel 60 around the exterior surface of theendoscope 20 using a frictional fit, as shown in FIG. 5. An interiorsurface of the proximal portion 62 may comprise a texture or material,such as rubber, configured to increase the frictional fit with theexterior surface of the endoscope 20.

If desired, a securing means may be applied to secure a portion of theproximal barrel 60 directly to an exterior surface of the endoscope 20to prohibit movement of the proximal barrel 60 with respect to theendoscope 20. For example, the securing means may comprise an adhesivetape, heat-shrink tubing, one or more tie-down bands, cable-ties, andthe like. The securing means may be configured and disposed so as to notinterfere with movement of the endoscope 20 through the patient. Furtherdetails of an exemplary securing means and techniques for securing acomponent, such as the proximal barrel 60, to an exterior surface of anendoscope are explained in U.S. Pat. Pub. No. 2007/0270897, thedisclosure of which is hereby incorporated by reference in its entirety.

The distal barrel 80 comprises proximal and distal regions 82 and 84,respectively, and a lumen 88 extending therebetween. The proximal region82 of the distal barrel 80 may be coupled to the distal region 64 of theproximal barrel 60, as shown in FIGS. 2-3. The proximal and distalbarrels 60 and 80 may be formed integrally, or may comprise two distinctsections that are coupled together at first and second separatingsegments 76 and 77. If two distinct sections are used, the proximal anddistal barrels 60 and 80 may comprise different materials and/orflexibilities. For example, the proximal barrel 60 may be at leastpartially formed from an elastic material to engage around the exteriorsurface of the endoscope 20 as noted above, while the distal barrel 80may be formed from a more rigid material that does not bend or flex whenthe cutting member 100 is advanced or rotated therein, as explainedfurther below.

In accordance with one aspect, the distal barrel 80 is radially offsetfrom the proximal barrel 60. In particular, the proximal barrel 60comprises a central longitudinal axis L₁, while the distal barrel 60comprises a central longitudinal axis L₂, whereby the centrallongitudinal axes L₁ and L₂ are not radially aligned, as shown in FIG.5. Notably, the working lumen 38 of the endoscope 20 is not radiallycentered within the endoscope 20, as is the case for most endoscopedesigns. Since the working lumen 38 is not centered within the endoscope20, the radial offset between central longitudinal axes L₁ and L₂ allowsthe proximal barrel 60 to be aligned with the exterior surface of theendoscope 20 along the central longitudinal axes L₁, and further allowsthe distal barrel 80 to be aligned with the working lumen 38 along thecentral longitudinal axes L₂, as shown in FIG. 5. Advantageously, thecutting member 100, when disposed within the distal barrel 80, iscentered relative to the working lumen 38. Further, when the actuatingmember 115 that is coupled to the cutting member 100 is disposed withinthe working lumen 38, an enhanced, centered rotation of the cuttingmember 100 within the distal barrel 80 may be achieved, as explainedfurther below.

A radius r₁ is formed between the central longitudinal axis L₁ of theproximal barrel 60 and an exterior surface of the proximal barrel 60, asshown in FIG. 5. Further, a radius r₂ is formed between the centrallongitudinal axis L₂ of the distal barrel 80 and an exterior surface ofthe distal barrel 80. In the embodiment shown, the radii r₁ and r₂ areidentical or approximately identical. However, the radius r₂ may belarger or smaller than radius r₁, depending on the diameter of thecutting instrument 100 that is desired as dictated, for example, by theparticular size of tissue to be resected. Accordingly, the relativediameters of the proximal and distal barrels 60 and 80 need not beidentical, but rather may vary depending on both the outer diameter ofthe endoscope 20 and the diameter of the cutting instrument 100.

Referring to FIG. 4, an exemplary cutting member 100 is shown inisolation. The cutting member 100 comprises a cylindrical main body 102having a beveled distal region 104. The main body 102 is generallyhollow and comprises a lumen 103 formed therein. The beveled distalregion 104 terminates in a sharpened distal tip 105, as shown in FIGS. 4and 6-7. The main body 102 preferably comprises a cylindrical exteriorsurface 108 having an outer diameter that is just smaller than an innerdiameter of the distal barrel 80. Therefore, the main body 102 and thebeveled distal region 104 of the cutting member 100 may belongitudinally and rotationally disposed within the lumen 88 of thedistal barrel 80, as shown in FIGS. 6-7.

In one embodiment, the main body 102 of the cutting member 100 iscoupled to the actuating member 115 by a proximal support section 110.The proximal support section 110 preferably comprises an outer diameteridentical to the main body 102, as shown in FIG. 4, and therefore may belongitudinally and rotationally disposed within the lumen 88 of thedistal barrel 80 along with the main body 102, as shown in FIGS. 6-7.The proximal support section 110 further comprises a central hub 112 anda plurality of supporting struts 113 a-113 d extending radially outwardfrom the central hub 112. The actuating member 115 is securely attachedto the central hub 112, e.g., using a friction fit, suitable mechanicalmeans, adhesive, solder, weld, or other suitable means.

The plurality of supporting struts 113 a-113 d are separated by aplurality of viewing windows 114 a-114 d, as shown in FIG. 4.Advantageously, the plurality of supporting struts 113 a-113 d providesupport to the main body 102, while the plurality of viewing windows 114a-114 d permit endoscopic visualization of tissue distal to the distalbarrel 80 when the cutting member 100 is disposed within the distalbarrel 80, as shown in FIGS. 6-7. While four supporting struts 113 a-113d and four viewing windows 114 a-114 d are shown, it will be apparentthat greater or fewer struts and windows may be provided.

Referring to FIGS. 6-7, an exemplary use of the endoscopic tissueresection system 50 is described to resect tissue T in a safe andeffective manner. In a first step, the endoscope 20 may be retrofittedusing the tissue resection system 50 by securing at least a portion ofthe proximal barrel 60 to the endoscope 20. For example, the proximalportion 62 may be disposed over the distal region 34 of the endoscope 20and secured using elastic properties of the proximal portion 62 and/oran external securing means, as explained above. Notably, the firstseparating segment 76 formed between the proximal barrel 60 and thedistal barrel 80 forms a step to prevent the distal barrel 80 from beingadvanced proximally over the endoscope 20, as depicted in FIG. 6.

The cutting member 100 is disposed within the lumen 88 of the distalbarrel 80, and is disposed for longitudinal and rotational movementrelative to the distal barrel 80. The second separating segment 77formed between the proximal barrel 60 and the distal barrel 80 forms astep to prevent proximal movement of the cutting member 100 outside ofthe distal barrel 80, as depicted in FIG. 6.

The cutting member 100 is disposed within the lumen 88 of the distalbarrel 80 in a retracted state, as shown in FIG. 6, where the sharpeneddistal tip 105 of the cutting member 100 is confined within the distalbarrel 80, i.e., the sharpened distal tip 105 is not exposed and cannotinadvertently cut tissue. At this time, the proximal support section 110of the cutting member 100 may abut the second separating segment 77. Theactuating member 115 extends proximally from the proximal supportsection 110, through the working lumen 38, and through the auxiliaryport 25 of the endoscope 20 for manipulation by a user.

The endoscope 20 may be advanced to a desired target site using suitableimaging techniques, such as the fiber optic components 36 and 37, anultrasound transducer, fluoroscopic techniques in conjunction withradiopaque bands, and the like. Once the physician has properlypositioned the device adjacent to the tissue T to be resected, aproximal end of the actuating member 115 is actuated to cause distaladvancement and/or rotation of the main body 102 and the beveled distalregion 104 relative to the distal barrel 80. The actuating member 115may comprise a torque cable or another suitable elongated member. Theactuating member 115 may be manipulated manually, or alternatively, theproximal end of the actuating member 115 may be coupled to an electricmotor, such as a drill, to facilitate controlled actuation of thecutting member 100, e.g., at the desired revolutions per minute (rpm).

The sharpened distal tip 105 engages and resects the selected portion ofthe tissue T, as shown in FIG. 7. When the desired amount of tissue T isresected and held within the lumen 103 of the main body 102 of thecutting member 100, the actuating member 115 may be proximally retractedsuch that the cutting member 100 assumes the retracted state shown inFIG. 6 for removal from the patient. The tissue resected has beencollected and may be evaluated upon removal of the endoscope 20.

Advantageously, the plurality of viewing windows 114 a-114 d permitendoscopic visualization of the tissue T being resected by the cuttingmember 100 during the process. Further, since the main body 102 of thecutting member 100 is centered relative to the working lumen 38, anenhanced, centered rotation of the cutting member 100 may be achieved.Additionally, the system 50 provides a simple endoscopic tissueresection system that may be used as a retrofit to an existing endoscope20.

In an alternative embodiment, shown in FIGS. 8-9, a distal barrel 80′includes a stop member 84′ configured to limit distal movement of analternative cutting member 100′. In this example, the stop member 84′ isformed as an inward taper at the distal end of the distal barrel 80′. Asshown in FIGS. 8-9, the stop member 84′ may cooperate with a portion ofthe beveled distal portion 104′ of the cutting member 100′ to inhibitfurther distal advancement of the cutting member 100′, thereby ensuringthat the proximal support section 110 and/or the main body 102′ of thecutting member 100′ remain inside of the distal barrel 80′. However, thesharpened distal tip 105′ is allowed to extend distal to the distalbarrel 80′ to achieve a resection of tissue. Notably, in thisembodiment, the cutting member 100′ may comprise a shorter main body102′ and a longer beveled distal portion 104′ to enable advancementwithin the distal barrel 80′ as shown in FIG. 9. As an advantage, in theembodiment of FIGS. 8-9, the inward taper of the stop member 84′ mayfacilitate a less traumatic entry of the endoscope 20 into a patient.While one exemplary stop member 84′ has been shown, other stop membersmay be provided to control the advancement of the cutting member.

The proximal and distal barrels 60 and 80 may be used in endoscopicapplications other than resection of tissue. Further, instruments otherthan the cutting member 100 may be used in conjunction with the proximaland distal barrels 60 and 80, for example, where it is desirable tocenter any instrument within a barrel and relative to the working lumen38 of the endoscope 20. Further, the proximal and distal barrels 60 and80 provided in accordance with the present embodiments may be used inconjunction with an array of existing commercial endoscopes.

Further, various techniques may be used to ensure an atraumatictransition between the proximal and distal barrels 60 and 80. Forexample, the first separating segment 76 may be tapered at an angle toavoid a relatively steep step and to promote a smooth transition betweenthe proximal and distal barrels 60 and 80. Additionally, the distal end84 of the distal barrel 80 may comprise atraumatic features to promote asmooth insertion towards a target site.

While various embodiments of the invention have been described, it willbe apparent to those of ordinary skill in the art that many moreembodiments and implementations are possible within the scope of theinvention. Accordingly, the invention is not to be restricted except inlight of the attached claims and their equivalents.

I claim:
 1. Apparatus for facilitating resection of tissue, theapparatus comprising: a proximal barrel adapted to be detachably coupledto a functional endoscope; a distal barrel coupled to the proximalbarrel, the distal and proximal barrels each having a lumen partiallyoverlapping with the lumen of the other, wherein the distal barrelcomprises an outer circumferential region forming a substantiallycircular shape; and a cutting member disposed within a lumen of thedistal barrel and configured to resect a segment of tissue, wherein acentral longitudinal axis of the proximal barrel is radially offset froma central longitudinal axis of the distal barrel, and wherein thecentral longitudinal axis of the distal barrel is radially aligned witha working lumen of the endoscope.
 2. The apparatus of claim 1 whereinthe cutting member comprises a cylindrical main body having a beveleddistal region.
 3. The apparatus of claim 1 wherein the cutting member isdisposed for longitudinal and rotational movement relative to the distalbarrel.
 4. The apparatus of claim 1 further comprising a stop memberadapted to limit maximum distal movement of the cutting member.
 5. Theapparatus of claim 1 wherein the cutting member is coupled to anactuating member disposed within the working lumen of the endoscope,wherein the actuating member is coupled to a proximal support section ofthe cutting member along a central longitudinal axis of the distalbarrel.
 6. The apparatus of claim 1 wherein a proximal support sectionof the cutting member comprises a plurality of supporting strutsseparated by a plurality of viewing windows, wherein the plurality ofviewing windows permit endoscopic visualization of tissue distal to thedistal barrel.
 7. The apparatus of claim 1 further comprising: a firstseparating segment formed between the proximal barrel and the distalbarrel, wherein the first separating segment prevents the distal barrelfrom being advanced proximally over the endoscope; and a secondseparating segment formed between the proximal barrel and the distalbarrel, wherein the second separating segment limits proximal movementof the cutting member.
 8. The apparatus of claim 1 wherein at least aportion of the proximal barrel is adapted to be disposed about anexterior surface of the endoscope and comprises an elastic member havinga larger diameter state adapted to be placed over the endoscope and asmaller diameter state that permits the proximal barrel to beelastically secured about the exterior surface of the endoscope.
 9. Theapparatus of claim 1 further comprising an endoscope, wherein theproximal barrel is disposed on a distal end of the endoscope.
 10. Amethod for facilitating resection of tissue, the method comprising:providing apparatus comprising a proximal barrel and a distal barrel,the distal and proximal barrels each having a lumen partiallyoverlapping with the lumen of the other; detachably coupling at least aportion of the proximal barrel to a functional endoscope; disposing acutting member within a lumen of the distal barrel; and actuating thecutting member in at least one of a longitudinal or rotational directionrelative to the distal barrel to resect a segment of tissue, wherein acentral longitudinal axis of the cutting member is radially aligned witha central longitudinal axis of the distal barrel.
 11. The method ofclaim 10 wherein a central longitudinal axis of the proximal barrel isradially offset from the central longitudinal axis of the distal barrel,wherein the central longitudinal axis of the distal barrel is alignedwith a working lumen of the endoscope.
 12. The method of claim 10wherein the cutting member comprises a cylindrical main body and abeveled distal region, the method further comprising longitudinallyadvancing and rotating the cutting member relative to the distal barrel.13. The method of claim 10 further comprising providing a stop member tolimit maximum distal movement of the cutting member.
 14. The method ofclaim 10 wherein the cutting member comprises at least one viewingwindow that permits endoscopic visualization of tissue distal to thedistal barrel.
 15. Apparatus for facilitating resection of tissue, theapparatus comprising: a proximal barrel adapted to be coupled to anendoscope; a distal barrel coupled to the proximal barrel; and a cuttingmember disposed within a lumen of the distal barrel and configured toresect a segment of tissue, wherein the cutting member is disposed forat least one of longitudinal and rotational movement relative to thedistal barrel, wherein the cutting member comprises at least one viewingwindow that permits endoscopic visualization of tissue distal to thedistal barrel, wherein a central longitudinal axis of the proximalbarrel is radially offset from a central longitudinal axis of the distalbarrel, and wherein the central longitudinal axis of the distal barrelis radially aligned with a working lumen of the endoscope.
 16. Theapparatus of claim 15 wherein the cutting member comprises a cylindricalmain body having a beveled distal region.
 17. The apparatus of claim 15wherein the cutting member is coupled to an actuating member disposedwithin the working lumen of the endoscope, wherein the actuating memberis coupled to a proximal support section of the cutting member along thecentral longitudinal axis of the distal barrel.
 18. The apparatus ofclaim 15 further comprising a stop member adapted to limit maximumdistal movement of the cutting member.